Fujifilm X-T30 II has a
26.0MP APS-C (23.5 x 15.6 mm ) sized X-Trans CMOS sensor and features X-Processor 4 processor. On the other hand, Sony a3500 has a
20.0MP APS-C (23.5 x 15.6 mm ) sized CMOS sensor and features BIONZ processor.
Fujifilm X-T30 II's sensor provides 6MP more than Sony a3500's sensor, which gives a significant advantage in real life. You can print your images larger or crop more freely.
On the other hand, please keep in mind that Max sensor resolution is not the only determinant of resolving power. Factors such as the optical elements, low pass filter, pixel size and sensor technology also affects the final resolution of the captured image.
Another difference between these two cameras is that Fujifilm X-T30 II's sensor lacks anti-alias (Low-Pass) filter. Removing anti-alias filter increases the sharpness and level of detail but at the same time, it increases the chance of moiré occurring in certain scenes.
Below you can see the X-T30 II and a3500 sensor size comparison.
Sensor Size and Resolution Comparison image of Fujifilm X-T30 II and Sony a3500 Cameras
Fujifilm X-T30 II and Sony a3500 have the same sensor sizes so they will provide same level of control over the depth of field when used with same focal length and aperture. On the other hand, since Sony a3500 has 31% larger pixel area (18.50µm 2 vs 14.12µm 2 ) compared to Fujifilm X-T30 II, it has larger pixel area to collect light hence potential to have less noise in low light / High ISO images.
Sensor size sets the circle of confusion, so it drives how much depth of field each
of these bodies gives you at a given aperture. You can calculate it exactly for the
Fujifilm X-T30 II
or the
Sony a3500 ,
including hyperfocal distance.